OptimizeInstructions: Optimize boolean selects (#4147)

If all a select's inputs are boolean, we can sometimes turn the select
into an AND or an OR operation,

x ? y : 0  =>  x & y
x ? 1 : y  =>  x | y

I believe LLVM aggressively canonicalizes to this form. It makes sense
to do here too as it is smaller (save the constant 0 or 1). It also allows
further optimizations (which is why LLVM does it) but I don't think we
have those yet.

1 files changed, 4 insertions, 4 deletions

diff --git a/test/wasm2js/i64-lowering.2asm.js.opt b/test/wasm2js/i64-lowering.2asm.js.opt
index 395b6f442..6d90214d2 100644
--- a/test/wasm2js/i64-lowering.2asm.js.opt
+++ b/test/wasm2js/i64-lowering.2asm.js.opt
@@ -22,19 +22,19 @@ function asmFunc(env) {
  }
  
  function legalstub$3($0, $1, $2, $3) {
-  return ($1 | 0) > ($3 | 0) ? 1 : ($1 | 0) >= ($3 | 0) ? $0 >>> 0 >= $2 >>> 0 : 0;
+  return ($1 | 0) >= ($3 | 0) & $0 >>> 0 >= $2 >>> 0 | ($1 | 0) > ($3 | 0);
  }
  
  function legalstub$4($0, $1, $2, $3) {
-  return ($1 | 0) > ($3 | 0) ? 1 : ($1 | 0) >= ($3 | 0) ? $0 >>> 0 > $2 >>> 0 : 0;
+  return $0 >>> 0 > $2 >>> 0 & ($1 | 0) >= ($3 | 0) | ($1 | 0) > ($3 | 0);
  }
  
  function legalstub$5($0, $1, $2, $3) {
-  return ($1 | 0) < ($3 | 0) ? 1 : ($1 | 0) <= ($3 | 0) ? $0 >>> 0 <= $2 >>> 0 : 0;
+  return ($1 | 0) <= ($3 | 0) & $0 >>> 0 <= $2 >>> 0 | ($1 | 0) < ($3 | 0);
  }
  
  function legalstub$6($0, $1, $2, $3) {
-  return ($1 | 0) < ($3 | 0) ? 1 : ($1 | 0) <= ($3 | 0) ? $0 >>> 0 < $2 >>> 0 : 0;
+  return $0 >>> 0 < $2 >>> 0 & ($1 | 0) <= ($3 | 0) | ($1 | 0) < ($3 | 0);
  }
  
  function legalstub$7($0, $1, $2, $3) {